We consider the Z′/Z mass hierarchy in a supersymmetric model in which the U(1)′ is broken in a secluded sector coupled to the ordinary sector only by gauge and possibly soft terms. A large mass hierarchy can be achieved while maintaining the normal sparticle spectra if there is a direction in which the tree level potential becomes flat when a particular Yukawa coupling vanishes. We describe the conditions needed for the desired breaking pattern, to avoid unwanted global symmetries, and for an acceptable effective μ parameter. The electroweak breaking is dominated by A terms rather than scalar masses, leading to tan β≈1. The spectrum of the symmetry breaking sector is displayed. There is significant mixing between the MSSM particles and new standard model singlets, for both the Higgs scalars and the neutralinos. A larger Yukawa coupling for the effective μ parameter is allowed than in the NMSSM because of the U(1)′ contribution to the running from a high scale. The upper bound on the tree-level mass of the lightest CP even Higgs doublet mass is about c x 174 GeV, where c is of order unity, but the actual mass eigenvalues are generally smaller because of singlet mixing.
|Original language||American English|
|Number of pages||1350192|
|Journal||Physical Review D - Particles, Fields, Gravitation and Cosmology|
|Issue number||1 II|
|State||Published - Jul 1 2002|
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)